Table 2

Multivariable logistic regression for restrictive spirometry pattern (vs normal spirometry) in 100 patients with sickle cell anaemia aged 6–18 years from the DR Congo

PredictorRestrictive spirometry pattern*
OR95% CIP value
Female sex3.81.2 to 11.60.02
Annual increase of age, years1.31.1 to 1.50.005
Frequent pain crises†0.40.1 to 1.40.16
zBMI <−25.41.6 to 17.60.006
  • ZBMI and zHeight values based on WHO growth charts.7

  • Spirometry z-scores based on Global Lung Function Initiative 2012 equations for African Americans.8

  • *Restrictive pattern=FVC <LLN and FEV1/FVC ≥LLN; only covariates with p value <0.20 were included in the final model.

  • †At least three episodes in the last 12 months. Pain crisis defined as bone pain in the chest, extremities or other areas that required at least 24 hours of analgesic therapy.

  • zBMI, z-score body mass index; zHeight, z-score height.